Method for manufacturing a radiator

ABSTRACT

A method of manufacturing radiators by joining a corrugated fin to a base plate, characterized by low costs and prevention of thermal deformation of the corrugated fin due to low-temperature soldering. A first soldering at the lower ends of the corrugated fin is conducted by a first soldering alloy in a recess heated by a heating plate in a mobile solder tank filled with the molten first soldering alloy. A second soldering alloy is heated by a heating plate on a base plate and the molten second soldering alloy is used to conduct a second soldering. When the corrugated fin is placed on the base plate, pressed and heated, the first and second solders are melted to join the corrugated fin to the base plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a 371 of PCT/JP00/07658 filed Oct. 31, 2000.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for manufacturing a radiatorwhich is used for heat radiation from a CPU or the like in a computer.

2. Description of Related Art

Heretofore, a manufacturing method of a radiator used for heat radiationfrom a CPU or the like in a computer has been disclosed in, for example,Japanese Patent Publication Laid-open No. 313080/1998.

This conventional example is a manufacturing method of a radiatorwherein a corrugate fin made by bending a metallic thin plate ofaluminum or the like into a corrugated shape is bonded onto a base plateby soldering.

Furthermore, Japanese Patent Publication Laid-open No. 204968/1999discloses a method wherein a fin made by extrusion molding is appliedonto a base plate by friction soldering or supersonic soldering to formsolder plating, and the solder-plated base plate and fin are bondedtogether by friction soldering.

However, the above-mentioned conventional example of Japanese PatentPublication Laid-open No. 313080/1998 has a problem wherein the bondedcorrugate fin is apt to be thermally deformed because it is bonded bysoldering in a high temperature state.

Moreover, the above-mentioned conventional example of Japanese PatentPublication Laid-open No. 204968/1999 has a problem wherein themanufacturing cost is high because the base plate has a structure inwhich an Ag layer is interposed between a Cu material and an Almaterial, and the final step is a step of bonding the solder-plated baseplate and fin together by friction soldering.

Accordingly, it is an object of the present invention to provide amanufacturing method of a radiator wherein a corrugate fin caninexpensively be bonded to a base plate, and the thermal deformation ofthe corrugate fin can be prevented by soldering at a low temperature.

SUMMARY OF THE INVENTION

The present invention is directed to a manufacturing method of aradiator comprising the steps of:

(1) manually or mechanically fitting a frame onto a corrugate fin madeof Al or an Al alloy and bent into a corrugated shape;

(2) manually or mechanically grasping said frame, moving it into aheated recess of a movable solder bath filled with a molten first solderalloy, horizontally moving said movable solder bath while the lower endsof said corrugate fin are dipped in said molten first solder alloy andthe lower ends are in a friction state with the bottom surface of saidrecess, and then applying the first plating of said molten first solderalloy onto the lower ends of said corrugate fin;

(3) heating and melting second solder alloy on a base plate made of oneof Cu, a Cu alloy, Al and an Al alloy, rubbing said base plate with ametallic brush which is manually or mechanically moved in a horizontaldirection, and then applying the second plating of said molten secondsolder thereunto; and

(4) manually or mechanically grasping said frame, putting said corrugatefin on said base plate, pressing and heating it on said base plate tothereby melt said first plating and said second plating and to bond saidcorrugate fin onto said base plate, and then removing said frame fromsaid corrugate fin.

Step (2) can be replaced with

a step (2a) of manually or mechanically grasping said frame, moving itinto a heated recess of a movable solder bath filled with a molten firstsolder alloy, horizontally moving said frame while the lower ends ofsaid corrugate fin are dipped in said molten first solder alloy and thelower ends are in a friction state with the bottom surface of saidrecess, and then applying the first plating of said molten first solderalloy onto the lower ends of said corrugate fin.

Step (3) can be replaced with

a step (3a) of heating and melting said second solder alloy on a baseplate made of one of Cu, a Cu alloy, Al and an Al alloy, bringing ametallic brush into contact therewith, manually or mechanically movingsaid base plate in a horizontal direction to rub said base plate withsaid metallic brush, and then applying the second plating of said moltensecond solder alloy thereunto.

Both steps (2a) and (3a) can be performed in combination.:

Step (2) can also be replaced with

a step (2b) of applying a flux to the lower ends of said corrugate finfitted in said frame, heating it, and then applying the first plating ofsaid first solder alloy onto the lower ends of said corrugate fin.

Step (3) can also be replaced with

a step (3b) of applying a flux onto a base plate made of one of Cu, a Cualloy, Al and an Al alloy, heating it, and then applying the secondplating of a second solder alloy onto said base plate.

Both steps (2b) and (3b) can be performed together.

Step (2) can also be replaced with

a step (2c) of manually or mechanically grasping said frame, and then,while dipping the lower ends of said corrugate fin in a third solderalloy which is molten, caused to flow, and subjected to ultrasonicvibration, applying the third plating of the molten third solder alloyonto the lower ends of said corrugate fin; and,

Step (3) can also be replaced with

a step (3c) of, while dipping a base plate made of one of Cu, a Cualloy, Al and an Al alloy in a fourth solder alloy which is molten,caused to flow, and subjected to ultrasonic vibration, applying thefourth plating of a fourth solder alloy onto said base plate.

In the present invention step (3), (3a), (3b) or (3c) can be a precedentstep to or a simultaneous step with said step (1),(2),(2a),(2b) or (2c).

In the present invention the entire body can be plated with one of Al,Ni, Cr, Ag and Au, or an alloy of them, after step (4).

In the present invention only a peripheral portion on said base platecan be covered with a metal mask in said step (3), (3a), (3b) or (3c),and said metal mask can be removed from said base plate in said step(4).

In the present invention said first to fourth solder alloys can be madeof Sn and Zn, or Zn and Al.

In the present invention said frame can be made of a metal, a ceramicmaterial or a heat-resistant synthetic resin.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustrative view of a step of the present invention;

FIG. 2 are illustrative views of a step of the present invention;

FIS. 3 are illustrative views of a step of the present invention;

FIG. 4 are illustrative views of a step of the present invention;

FIG. 5 is an illustrative view of a step of the present invention; and

FIG. 6 is an illustrative view of a step according to another embodimentof the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention will be described on the basis of itsembodiments.

According to the present invention, as shown in FIG. 1, step (1) isshown where a frame 2 is fitted onto a corrugate fin 1 made of Al or anAl alloy and bent into a corrugated shape, not-shown manually ormechanically with a robot or the like.

Next, as shown in FIGS. 2(a) and (b), step (2) is shown where the frame2 is grasped not-shown manually or mechanically with a robot or thelike, it is moved into a recess 5 heated with a heating plate 6 of amovable solder bath 4 filled with a molten first solder alloy 3, themovable solder bath 4 is moved horizontally 7 while the lower ends ofthe corrugate fin 1 are dipped in the molten first solder alloy 3 andthe lower ends are in a friction state with a bottom surface of therecess 5, and thereby the first plating of the molten first solder alloy3 is applied onto the lower ends of the corrugate fin 1.

Next, as shown in FIGS. 3(a) and (b), step (3) is shown where a secondsolder alloy 9 is heated with a heating plate 13 and molten on a baseplate 8 made of one of Cu, a Cu alloy, Al and an Al alloy, and the baseplate 8 is rubbed with a metallic brush 12 which is moved by a not shownmanual means or mechanically by a robot or the like in a horizontaldirection 11 as shown in FIGS. 4(a) and (b), and the second plating ofthe molten second solder alloy 9 is then applied thereunto. Here, thereis also a case that only a peripheral portion on the base plate 8 iscovered with a metal mask 10.

Next, as shown in FIG. 5, step (4) is shown where the corrugate fin 1 isput on, pressed onto, and heated on the base plate 8 with grasping theframe 2 not-shown manually or mechanically with a robot or the like, thefirst plating and the second plating is thereby molten to bond thecorrugate fin 8 onto the base plate 8, and then the frame 8 is removedfrom said corrugate fin. Here, in case of having the metal mask 10, itis also removed.

Therefore, because of not a friction soldering step but a staticsoldering step in the final step (4), the corrugate fin 1 caninexpensively be bonded to the base plate 2, and the thermal deformationof the corrugate fin 1 can be prevented due to soldering at a lowtemperature.

According to the present invention step (2) can be replaced with a step(2a) wherein, in FIG. 1, inversely, the frame 2 is grasped not-shownmanually or mechanically with a robot or the like; it is moved into aheated recess 5 of a movable solder bath 4 filled with a molten firstsolder alloy 3; the frame 2 is moved horizontally 7 while the lower endsof the corrugate fin 1 are dipped in said molten first solder alloy 3and the lower ends are in a friction state with a bottom surface of therecess 5; and the first plating of the molten first solder alloy 3 isapplied onto the lower ends of the corrugate fin 1.

Therefore, because of not a friction soldering step but a staticsoldering step in the final step (4), the corrugate fin 1 caninexpensively be bonded to the base plate 2, and the thermal deformationof the corrugate fin 1 can be prevented due to soldering at a lowtemperature.

According to the present invention step (3) can be replaced with a step(3a) wherein, in FIG. 1, inversely, a second solder alloy 9 is heatedand molten on a base plate 8 made of one of Cu, a Cu alloy, Al and an Alalloy; a metallic brush 12 is brought into contact therewith; the baseplate 8 is moved by a not shown manual means or mechanically by a robotor the like in a horizontal direction to rub the base plate 8 with themetallic brush 12; and the second plating of the molten second solderalloy 9 is then applied thereto.

Therefore, because of not a friction soldering step but a staticsoldering step in the final step (4), the corrugate fin 1 caninexpensively be bonded to the base plate 2, and the thermal deformationof the corrugate fin 1 can be prevented due to soldering at a lowtemperature.

According to the present invention step (2a) and (3b) can be combinedsuch that step (2) is replaced with a step (2a) wherein the frame 2 isgrasped not-shown manually or mechanically with a robot or the like; itis moved into a heated recess 5 of a movable solder bath 4 filled with amolten first solder alloy 3; the frame 2 is moved horizontally 7 whilethe lower ends of the corrugate fin 1 are dipped in the molten firstsolder alloy 3 and the lower ends are in a friction state with a bottomsurface of the recess 5; and the first plating of the molten firstsolder alloy 3 is applied onto the lower ends of the corrugate fin 1,and,

step (3) is replaced with a step (3a) wherein a second solder alloy 9 isheated and molten on a base plate 8 made of one of Cu, a Cu alloy, Aland an Al alloy; a metallic brush 12 is brought into contact therewith;the base plate 8 is manually or mechanically moved in a horizontaldirection to rub the base plate 8 with the metallic brush 12; and thesecond plating of the molten second solder alloy 9 is then appliedthereto.

Therefore, because of not a friction soldering step but a staticsoldering step in the final step (4), the corrugate fin 1 caninexpensively be bonded to the base plate 2, and the thermal deformationof the corrugate fin 1 can be prevented due to soldering at a lowtemperature.

According to the present invention step (2) or (2a) can be replaced witha step (2b) wherein, in FIG. 1, a flux is applied to the lower ends ofthe corrugate fin 1 fitted in the frame 2; it is heated; and the firstplating of the first solder alloy 3 is applied onto the lower ends ofthe corrugate fin 1.

Therefore, because of not a friction soldering step but a staticsoldering step in the step (2b), (4), the corrugate fin 1 caninexpensively be bonded to the base plate 2, and the thermal deformationof the corrugate fin 1 can be prevented due to soldering at a lowtemperature.

According to the present invention step (3) or (3a) can be replaced witha step (3b) wherein, in FIG. 1, a flux is applied onto a base plate 2made of one of Cu, a Cu alloy, Al and an Al alloy; it is heated; and thesecond plating of a second solder alloy 9 is applied onto the base plate2.

Therefore, because of not a friction soldering step but a staticsoldering step in the step (3b), (4), the corrugate fin 1 caninexpensively be bonded to the base plate 2, and the thermal deformationof the corrugate fin 1 can be prevented due to soldering at a lowtemperature.

According to the present invention steps (2b) and (3b) can be combinedsuch that, in FIG. 1, a flux is applied to the lower ends of thecorrugate fin 1 fitted in the frame 2; it is heated; and thereby thefirst plating of the first solder alloy 3 is applied onto the lower endsof the corrugate fin 1, and,

a flux is applied onto a base plate 8 made of one of Cu, a Cu alloy, Aland an Al alloy; it is heated; and thereby the second plating of asecond solder alloy 9 onto the base plate 8.

Therefore, because of not a friction soldering step but a staticsoldering step in the step (2b), (3b), (4), the corrugate fin 1 caninexpensively be bonded to the base plate 2, and the thermal deformationof the corrugate fin 1 can be prevented due to soldering at a lowtemperature.

According to the present invention step (2) can be replaced with a step(2c) wherein, as shown in FIG. 6, the frame 2 is grasped not-shownmanually or mechanically with a robot or the like; while the lower endsof the corrugate fin 1 typically shown are moved vertically 17 orhorizontally 18 and are dipped in a third solder alloy 16 which ismolten, caused to flow by a fan 14, and subjected to ultrasonicvibration by a supersonic oscillator 15, the third plating of the moltenthird solder alloy 16 is applied onto the lower ends of the corrugatefin 1.

Further, step (3) can be replaced with a step (3c) wherein, as shown inFIG. 6, while a base plate 8 made of one of Cu, a Cu alloy, Al and an Alalloy is moved vertically 17 or horizontally 18 with being verticallyinverted and dipped in a fourth solder alloy 19 which is molten, causedto flow by a fan 14, and subjected to ultrasonic vibration by asupersonic oscillator 15; and the fourth plating of the fourth solderalloy 19 is applied onto the base plate 8.

Therefore, because of not a friction soldering step but a staticsoldering step in the final step (4), the corrugate fin 1 caninexpensively be bonded to the base plate 2, and the thermal deformationof the corrugate fin 1 can be prevented due to soldering at a lowtemperature.

According to the present invention, step (3), (3a), (3b), or (3c) is aprecedent step to or a simultaneous step with said step(1),(2),(2a),(2b) or (2c).

Therefore, various manufacturing steps can be selected. This isconvenient.

According to the present invention, because the entire body is platedwith one of Al, Ni, Cr, Ag, and Au, or an alloy of them after said step(4), a radiator superior in anti-corrosion can be manufactured.

According to the present invention, only a peripheral portion on thebase plate 8 is covered with a metal mask in said step (3), (3a), (3b),or (3c), and said metal mask 10 is removed from the base plate 8 in saidstep (4).

Therefore, because of the metal mask 10, the peripheral portion on thebase plate 8 is not plated. This portion can be used for variousapplications.

According to the present invention, because said first to fourth solderalloys are made of Sn, Zn, or Zn, Al, the wettability of the solderbonding portion becomes good. But, the present invention is not limitedto these materials.

According to the present invention, the frame 2 is made of a metal suchas an Fe alloy, a ceramic material or a heat-resistant synthetic resinsuch as a polyimide, and therefore, this frame 2 is strong and notdeformed by heat.

As shown in FIG. 1, step (1) is shown where a frame 2 is fitted onto acorrugate fin 1 made of Al or an Al alloy and bent into a corrugatedshape, not-shown manually or mechanically with a robot or the like. Inthe interior of the frame 2, not shown partitions may properly beprovided so as to fit with the corrugate fin 1 bent into the corrugatedshape.

Next, as shown in FIGS. 2(a) and (b), step (2) is shown where the frame2 is grasped not-shown manually or mechanically with a robot or the likeand moved into a recess 5 heated with a heating plate 6 of a movablesolder bath 4 filled with a molten first solder alloy 3, the movablesolder bath 4 is moved horizontally 7 while the lower ends of thecorrugate fin 1 are dipped in the molten first solder alloy 3 and thelower ends are in a friction state with a bottom surface of the recess5, and thereby the first plating of the molten first solder alloy 3 isapplied onto the lower ends of the corrugate fin 1.

Next, as shown in FIGS. 3(a) and (b), step (3) is shown where a secondsolder alloy 9 is heated with a heating plate 13 and molten on a baseplate 8 made of one of Cu, a Cu alloy, Al and an Al alloy, a metallicbrush 12 not-shown manually or mechanically moving horizontally 11 witha robot or the like as shown in FIGS. 4(a) and (b) is slid in frictionon the base plate 8, and thereby the second plating of the molten secondsolder alloy 9 is applied. Here, there is also a case that only aperipheral portion on the base plate 8 is covered with a metal mask 10.

Next, as shown in FIG. 5, step (4) is shown where the corrugate fin 1 isput on, pressed onto, and heated on the base plate 8 with grasping theframe 2 not-shown manually or mechanically with a robot or the like, thefirst plating and the second plating is thereby molten to bond thecorrugate fin 1 onto the base plate 8, and then the frame 2 is removedfrom said corrugate fin. Here, in case of having the metal mask 10, itis also removed.

Next, in a manufacturing method of a radiator according to anotherembodiment of the present invention, the above step (2) is replaced witha step (2a) wherein, in FIG. 1, inversely, the frame 2 is graspednot-shown manually or mechanically with a robot or the like; it is movedinto a heated recess 5 of a movable solder bath 4 filled with a moltenfirst solder alloy 3; the frame 2 is moved horizontally 7 while thelower ends of the corrugate fin 1 are dipped in said molten first solderalloy 3 and the lower ends are in a friction state with a bottom surfaceof the recess 5; and thereby the first plating of the molten firstsolder alloy 3 is applied onto the lower ends of the corrugate fin 1.

Next, in a manufacturing method of a radiator according to anotherembodiment of the present invention, the above step (3) is replaced witha step (3a) wherein, in FIG. 1, inversely, a second solder alloy 9 isheated and molten on a base plate 8 made of one of Cu, a Cu alloy, Aland an Al alloy; a metallic brush 12 is brought into contact; the baseplate 8 is moved by a not shown manual means or mechanically by a robotor the like in a horizontal direction to rub the base plate 8 with themetallic brush 12; and the second plating of the molten second solderalloy 9 is applied.

Next, in a manufacturing method of a radiator according to anotherembodiment of the present invention, the above step (2) is replaced witha step (2a) wherein the frame 2 is grasped not-shown manually ormechanically with a robot or the like; it is moved into a heated recess5 of a movable solder bath 4 filled with a molten first solder alloy 3;the frame 2 is moved horizontally 7 while the lower ends of thecorrugate fin 1 are dipped in the molten first solder alloy 3 and thelower ends are in a friction state with a bottom surface of the recess5; and the first plating of the molten first solder alloy 3 is appliedonto the lower ends of the corrugate fin 1.

Furthermore, the above step (3) is replaced with a step (3a) wherein asecond solder alloy 9 is heated and molten on a base plate 8 made of oneof Cu, a Cu alloy, Al and an Al alloy; a metallic brush 12 is broughtinto contact therewith;

the base plate 8 is manually or mechanically moved in a horizontaldirection to rub the base plate 8 with the metallic brush 12; and thesecond plating of the molten second solder alloy 9 is applied thereto.

Next, in a manufacturing method of a radiator according to anotherembodiment of the present invention, the above step (2) or (2a) isreplaced with a step (2b) wherein, in FIG. 1, a flux is applied to thelower ends of the corrugate fin 1 fitted in the frame 2; it is heated;and the first plating of the first solder alloy 3 is applied onto thelower ends of the corrugate fin 1.

Next, in a manufacturing method of a radiator according to anotherembodiment of the present invention, the above step (3) or (3a) isreplaced with a step (3b) wherein, in FIG. 1, a flux is applied onto abase plate 8 made of one of Cu, a Cu alloy, Al and an Al alloy; it isheated; and the second plating of a second solder alloy 9 is appliedonto the base plate 8.

Next, in a manufacturing method of a radiator according to anotherembodiment of the present invention, the above step (2) or (2a) isreplaced a step (2b) wherein, in FIG. 1, a flux is applied to the lowerends of the corrugate fin 1 fitted in the frame 2; it is heated; andthereby the first plating of the first solder alloy 3 is applied ontothe lower ends of the corrugate fin 1, and,

the above step (3) or (3a) is replaced with a step (3b) wherein, a fluxis applied onto a base plate 8 made of one of Cu, a Cu alloy, Al and anAl alloy; it is heated; and the second plating of a second solder alloy9 is applied onto the base plate 8.

Next, in a manufacturing method of a radiator according to anotherembodiment of the present invention, the above step (2) is replaced witha step (2c) wherein, as shown in FIG. 6, the frame 2 is graspednot-shown manually or mechanically with a robot or the like; while thelower ends of the corrugate fin 1 typically shown are moved vertically17 or horizontally 18 and are dipped in a third solder alloy 16 which ismolten, caused to flow by a fan 14, and subjected to ultrasonicvibration by a supersonic oscillator 15; the third plating of the moltenthird solder alloy 16 is applied onto the lower ends of the corrugatefin 1.

Further, the above step (3) is replaced with a step (3c) wherein, asshown in FIG. 6, while a base plate 8 made of one of Cu, a Cu alloy, Aland an Al alloy is moved vertically 17 or horizontally 18 with beingvertically inverted and dipped in a fourth solder alloy 19 which ismolten, caused to flow by a fan 14, and subjected to ultrasonicvibration by a supersonic oscillator 15; and the fourth plating of thefourth solder alloy 19 is applied onto the base plate 8.

Next, in a manufacturing method of a radiator according to anotherembodiment of the present invention, said step (3), (3a), (3b), or (3c)is a precedent step to or a simultaneous step with said step(1),(2),(2a),(2b) or (2c).

Here, in the above present invention, the entire body is plated with oneof Al, Ni, Cr, Ag, and Au, or an alloy of them after said step (4).

Further, in the above present invention, only a peripheral portion onthe base plate 8 is covered with a metal mask in said step (3), (3a),(3b), or (3c), and said metal mask 10 is removed from the base plate 8in said step (4).

Further, in the above present invention, the first to fourth solderalloys are made of Sn, Zn, or Zn, Al. But, the present invention is notlimited to these materials.

Furthermore, in the above present invention, the frame is made of metalsuch as an Fe alloy, ceramic, or a heat-resistant synthetic resin suchas a polyimide.

What is claimed is:
 1. A manufacturing method of a radiator comprisingthe steps of: (1) manually or mechanically fitting a frame onto acorrugate fin made of Al or an Al alloy and bent into a corrugatedshape; (2) a first plating accomplished by a step of manually ormechanically grasping said frame, moving it into a heated recess of amovable solder bath filled with a molten first solder alloy,horizontally moving said movable solder bath while the lower ends ofsaid corrugate fin are dipped in said molten first solder alloy and thelower ends are in a friction state with the bottom surface of saidrecess, and then applying the first plating of said molten first solderalloy onto the lower ends of said corrugate fin; (3) a second platingaccomplished by a step of heating and melting second solder alloy on abase plate made of one of Cu, a Cu alloy, Al and an Al alloy, rubbingsaid base plate with a metallic brush which is manually or mechanicallymoved in a horizontal direction, and then applying the second plating ofsaid molten second solder thereunto; and (4) manually or mechanicallygrasping said frame, putting said corrugate fin on said base plate,pressing and heating it on said base plate to thereby melt said firstplating and said second plating and to bond said corrugate fin onto saidbase plate, and then removing said frame from said corrugate fin.
 2. Themanufacturing method of the radiator according to claim 1, wherein: saidfirst plating is accomplished by a step (2a) of manually or mechanicallygrasping said frame, moving it into a heated recess of a movable solderbath filled with a molten first solder alloy, horizontally moving saidframe while the lower ends of said corrugate fin are dipped in saidmolten first solder alloy and the lower ends are in a friction statewith the bottom surface of said recess, and then applying the firstplating of said molten first solder alloy onto the lower ends of saidcorrugate fin.
 3. The manufacturing method of the radiator according toclaim 1, wherein: said second plating is accomplished by a step (3a) ofheating and melting said second solder alloy on a base plate made of oneof Cu, a Cu alloy, Al and an Al alloy, bringing a metallic brush intocontact therewith, manually or mechanically moving said base plate in ahorizontal direction to rub said base plate with said metallic brush,and then applying the second plating of said molten second solder alloythereunto.
 4. The manufacturing method of the radiator according toclaim 1, wherein: said first plating is accomplished by a step (2a) ofmanually or mechanically grasping said frame, moving it into a heatedrecess of a movable solder bath filled with a molten first solder alloy,horizontally moving said frame while the lower ends of said corrugatefin are dipped in said molten first solder alloy and the lower ends arein a friction state with the bottom surface of said recess, and thenapplying the first plating of said molten first solder alloy onto thelower ends of said corrugate fin; and, said second plating isaccomplished by a step (3a) of heating and melting said second solderalloy on a base plate made of one of Cu, a Cu alloy, Al and an Al alloy,bringing a metallic brush into contact therewith, manually ormechanically moving said base plate in a horizontal direction to rubsaid base plate with said metallic brush, and then applying the secondplating of said molten second solder alloy thereunto.
 5. Themanufacturing method of a radiator according to claim 1 wherein: saidfirst plating is accomplished by a step (2b) of applying a flux to thelower ends of said corrugate fin fitted in said frame, heating it, andthen applying the first plating of said first solder alloy onto thelower ends of said corrugate fin.
 6. The manufacturing method of aradiator according to claim 1 wherein: said second plating isaccomplished by a step (3b) of applying a flux onto a base plate made ofone member of the group consisting of Cu, a Cu alloy, Al and an Alalloy, heating it, and then applying the second plating of a secondsolder alloy onto said base plate.
 7. The manufacturing method of theradiator according to claim 1, wherein: said first plating isaccomplished by a step (2b) of applying a flux to the lower ends of saidcorrugate fin fitted in said frame, heating it, and then applying thefirst plating of said first solder alloy onto the lower ends of saidcorrugate fin; and, said second plating is accomplished by a step (3b)of applying a flux onto a base plate made of one member of the groupconsisting of Cu, a Cu alloy, Al and an Al alloy, heating it, and thenapplying the second plating of a second solder alloy onto said baseplate.
 8. The manufacturing method of the radiator according to claim 1,wherein: said first plating is accomplished by a step (2c) of manuallyor mechanically grasping said frame, and then, while dipping the lowerends of said corrugate fin in a third solder alloy which is molten,caused to flow, and subjected to ultrasonic vibration, applying thethird plating of the molten third solder alloy onto the lower ends ofsaid corrugate fin; and, said second plating is accomplished by a step(3c) of, while dipping a base plate made of one member of the groupconsisting of Cu, a Cu alloy, Al and an Al alloy in a fourth solderalloy which is molten, caused to flow, and subjected to ultrasonicvibration, applying the fourth plating of a fourth solder alloy ontosaid base plate.
 9. The manufacturing method of the radiator accordingto claim 1, wherein: said step (3) is a precedent step to or asimultaneous step with said step (1) or (2).
 10. The manufacturingmethod of the radiator according to claim 1, wherein the entire body isplated with one member of the group consisting of Al, Ni, Cr, Ag and Au,or an alloy of the said metals, after said step (4).
 11. Themanufacturing method of the radiator according to claim 1, wherein onlya peripheral portion on said base plate is covered with a metal mask insaid step (3) and said metal mask is removed from said base plate insaid step (4).
 12. The manufacturing method of the radiator according toclaim 1, wherein said first to fourth solder alloys are made of Sn andZn, or Zn and Al.
 13. The manufacturing method of the radiator accordingto claim 1, wherein said frame is made of material selected from thegroup consisting of a metal, a ceramic material and a heat-resistantsynthetic resin.
 14. The manufacturing method of the radiator accordingto claim 2 wherein said step (3) is precedent to or a simultaneous stepwith said step (1) or step (2a).
 15. The manufacturing method of theradiator according to claim 3 wherein said step (3a) is precedent to ora simultaneous step with said step (1) or step (2).
 16. Themanufacturing method of the radiator according to claim 4 wherein saidstep (3a) is precedent to or a simultaneous step with said step (1) orstep (2a).
 17. The manufacturing method of the radiator according toclaim 5 wherein said step (3) is precedent to or a simultaneous stepwith said step (1) or step (2b).
 18. The manufacturing method of theradiator according to claim 6 wherein said step (3b) is precedent to ora simultaneous step with said step (1) or step (2).
 19. Themanufacturing method of the radiator according to claim 7 wherein saidstep (3b) is precedent to or a simultaneous step with said step (1) orstep (2b).
 20. The manufacturing method of the radiator according toclaim 8 wherein said step (3c) is precedent to or a simultaneous stepwith said step (1) or step (2c).